This invention relates generally to locks and, more particularly, to a cylinder lock with a locking core that can be removed with a proper key.
A substantial cost of maintaining many security systems involves the required removal of locks from the structures on which they have been installed. For example, security reasons necessitate lock removal for rekeying of a lock in certain instances. The requirement for rekeying can result from either a loss of keys to the lock or the termination of an employee having had access to a key for the lock. Lock removal also can be required to effect repair of a faulty lock.
The lock removal problem is somewhat alleviated in a type of lock commercially known as a Best cylinder lock. The Best lock employs a latching mechanism that can be actuated by a proper key to permit removal of a locking core from the lock's housing. Although substantially reducing the time required for lock removal and thereby the cost of either rekeying or repair, the Best locks exhibit the disadvantages of relatively high cost and a size that is excessive for many applications.
Other key removable locks are disclosed in U.S. Pat. Nos. 1,986,676 and 4,191,037 and in U.S. Application Ser. No. 06/055,925 filed July 6, 1979, and assigned to the assignee of this application. Although useful in many applications, these locks also suffer from various individual and common disadvantages such as the requirement for additional parts or for special manufacturing and assembling techniques. In addition, prior key removable locks have required a master key for lock removal and have therefore been subject to removal by anyone in possession of a master key. This is undesirable in that there are instances in which the functions associated with a master key and those of lock removal should not be available to the same personnel.
The object of this invention, therefore, is to provide an improved, relatively low cost cylinder lock having operational flexibility, reasonable security and a locking core that can be easily removed with a control key.